Acioa edulis

Acioa edulis of the family Chrysobalanaceae. (The tree's Portuguese common name: Castanha-de-cutia; syn. Couepia edulis (Prance) Prance) is a fruit and timber tree, which is native of Amazon Rainforest vegetation in Brazil. The trees grow naturally only within a small area of Brazil. However, they proliferate widely within this area. The tree is around 25 meters (82 feet) tall, with entire leaves that are oval or round, measuring three or four inches (8 to 10 centimeters) in diameter, with a petiole up to one inch (2.5 centimeters) in length. Its fruits range from 8-9 centimeters (3 to 3.5 inches) in length and 4-5 centimeters (1.75 to 2 inches) in diameter. and contain a single nut. Later these nuts float on the waters and have been collected for centuries as the source of a valuable oil, but their source was unknown until 1978 when botanical explorer Ghillean Prance discovered the species of tree which produces them.

Cultivation
The fruit is edible or can be pressed to extract oil used in cooking or soap making. The kernel is also edible.